LOD terrain rendering algorithm based on vertex texture

Vertex Shader Fetch introduced by Shader Mode 3.0, is an important progress of GPU (Graphic Process Unit). Based on this technology, a new terrain rendering algorithm was proposed. The main feature of this algorithm is that terrain elevation data is reformed into a lumen texture to support viewpoint fallowed LOD (Levels of detail) terrain rendering. In real-time rendering phase, what CPU does is just sending a flat and nested grid to GPU, while GPU computes the real 2D coordinate for every vertex depending on current view parameters, using such coordinate to fetch elevation value from the lumen texture. After that, three coordinate value of a vertex are ready, GPU continues to do the rest operation to show the terrain grid. To arrange render operation like that, not only computing load of CPU is reduced thoroughly, but also powerful computing capability of GPU and its feature of Programmable are applied. Experimental results show that, to do Terrain rendering by this algorithm, while getting realistic rendering effect, efficiency is much higher than traditional LOD Terrain Rendering Algorithm.